Using a variable inside a worksheet reference in a formula

I am new to the forum so hopefully this is the right place to post this.

=(INT(J4)+(J4-INT(J4))/60*100)-(INT(VVINSTAC173RT!J4)+(VVINSTAC173RT!J4-INT(VVINSTAC173RT!J4))/60*100)+VVINSTAC173RT!N$4

Here is my problem;

I am trying to work with a master worksheet. I want to be able to have all of my formulas on it and when I need to be able to copy and move in into another excel file. Is there a way to reference a excel worksheet name and have a section of it as a variable depending on what file I copy the mast sheet into?

I want 173RT to be a variable that is replaced by whatever value is in C4 depending on what file I copy my master sheet into.

If I am not using the write wording I will be more specific with what I am actually working with.